import java.util.Scanner;

/**
 * Created with IntelliJ IDEA.
 * Description: 牛客网.简单题.数列的和
 */

class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        while(scanner.hasNextInt()){
            double sum = 0;
            double n = scanner.nextDouble();
            int m = scanner.nextInt();
            for(int i = 0; i < m; i++) {
                sum += n;
                n = Math.sqrt(n);
            }
            System.out.printf("%.2f\n",sum);
        }
    }
}

public class Test {
}
